Air injection system for internal combustion engines

ABSTRACT

An air injection system arranged to admit air under pressure into the combustion chamber of an internal combustion engine for reducing waste products of combustion and also increasing the efficiency of the engine. A valve assembly is mounted on the engine for communication at one of its ends to the combustion chamber and for communication at its other end to a pressure supply line for admitting cold air to the valve. The valve assembly includes a ball valve and plunger which automatically control the flow of air from the pressure supply line into the combustion chamber. The valve mechanism is arranged such that air is admitted to the combustion chamber precisely as the piston approaches the end of the compression stroke. In a preferred arrangement, the valve housing has a base by means of which such housing is clamped in place by the existing spark plug, with ports being bored adjacent to the spark plug for directing the air into the combustion chamber.

United States Patent 11 1 Hunt,

[ AIR INJECTION SYSTEM FOR INTERNAL COMBUSTION ENGINES [76] Inventor:John 11. Hunt, 8030 SE. Barbar Welch, Portland, Oreg.

[22] Filed: Apr. 20, 1971 [21] App]. No.: 135,709

PrimaryExaminer-Wendell E. Burns Attorney-Eugene M. Eckelman [5 7]ABSTRACT An air injection system arranged to admit air under pressureinto the combustion chamber of an internal combustion engine forreducing waste products of combustion and also increasing the efficiencyof the engine. A valve assembly is mounted on the engine forcommunication at one of its ends to the combustion chamber and forcommunication at its other end to a pressure supply line for admittingcold air to the valve. The valve assembly includes a ball valve andplunger which automatically control the flow of air from the pressuresupply line into the combustion chamber. The valve mechanism is arrangedsuch that air is admitted to the combustion chamber precisely as thepiston approaches the end of the compression stroke. In a preferredarrangement, the valve housing has a base by means of which such housingis clamped in place by the existing spark plug, with ports being boredadjacent to the spark plug for directing the air into the combustionchamber,

2 Claims, 4 Drawing Figures PATENTEbmze ma ATTY.

BACKGROUND OF THE INVENTION This invention relates to new and usefulimprovements in air injection systems for internal combustion engines.

It is well recognized that during the operation of internal combustionengines, a portion of the fuel remains unburned and is discharged fromthe exhaust system' as pollutants. A reason for the inefficient burningis that there is insufficient air within the combustion chamber topermit complete combustion of all the fuel mixture introduced. Suchinefficiency particularly exists during idling because of the rich fuelmixture required.

It has been found heretofore that more complete combustion and thusgreater efficiency is accomplished by the introduction of air inaddition to that in the air fuel mixture. Such prior systems haveintroduced such additional air during the expansion stroke or during thestroke immediately following ignition.

SUMMARY OF THE INVENTION According to the present invention, there isprovided an air injection system arranged to admit auxiliary air into acombustion chamber of an internal combustion engine during thecompression stroke and preferably at a time when the piston approachesthe end of such compression stroke, thus provides better combustiondevice is clamped in place by the spark plug.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic view of thepresent invention as applied to an engine;

FIG. 2 is a longitudinal sectional view of valve mechanism of theinvention showing in detail its application to a vehicle engine;

FIG. 3 is a cross sectional view taken on the line 3-3 of FIG. 2; and

FIG. 4 is a longitudinal sectional view of a modified form of valveemploying the concept of the present in vention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Referring in particularto the drawings, and f'u'st to FIG. 1, the numeral designates aninternal combustion engine of conventional construction, having a headportion 12 and one or more spark plugs 14]. A combustion chamber 16,FIG. 2, is associated with the spark plug and the latter has a bottomthreaded shank 18 threadedly engaged with a tapped bore 20 in the head.

Forming a part of the present air injection system is an air pump 22driven by the vehicle engine in a well known manner, such as from thefan belt. Pump 22 supplies air under pressure to a line 24 through areserve tank 26 and is capable of supplying a pressure greater than thepressure existing in at least most of the compression stroke of thepiston. Line 26 leads to a valve mechanism 28 forming a part of thepresent invention. Such line may extend to other valve mechanisms, notshown, in a multiple cylinder engine since each cylinder has its ownvalve mechanism.

With particular reference to FIGS. 2 and 3, valve mechanism 26 comprisesa housing 36 having a bottom stem 32 provided with a passageway Mtherethrough. This stem may be cast as a part of the housing or have athreaded mounting 35 thereon as shown, and leads to an integral base 36having a bottom opening recess 38 in communication with passageway 34!.A smooth vertical bore 60 leads down through the top of the base 36 andis adapted to receive the threaded shank 18 of the spark plug, therecess 3% being of larger diameter than bore 40 so that an annularpassageway 42 is provided around the shank of the spark plug in thebase. The valve housing is supported on the head of the engine byclamping engagement of the base 36 by the spark plug, as illustrated inFIG. 2, and for the purpose of providing communication of the passageway42 with the combustion chamber 16 the head 12 is provided with one ormore ports M adjacent to the spark plug bore 20 and position so as tocommunicate at their upper ends with the passageway 42.

Valve housing Bill includes an insert 46 having a threaded connection 48with the valve housing 30 at the end opposite from the stem 32. Thisinsert has a bottom extension 50 below the threaded portion thereofwhich is of reduced diameter to provide an annular passageway 52 betweensuch reduced portion and the inside surface of the valve housing.

Insert 46 has a bore 54 leading upwardly through the bottom thereof, andthis bore communicates with a counterbore 56 in turn communicating witha counterbore 58 opening through the upper end of the insert. The upperend of counterbore 56 has a threaded connection 60 with a fitting 62connected to air line 24. Fitting 62 has a head 63 between its ends andis provided with a bore 64 therethrough of smaller diameter than thecounterbore 58.

Disposed in the counterbore 58 is a ball valve 68 adapted to operatebetween a lower seat 70 formed between counterbores 56 and 56 in theinsert 46 and an upper seat 72 formed in the end of fitting 62. The ballvalve 68 is smaller in diameter than the counterbore 58 so that air maybypass the said valve at selected times as will be described in greaterdetail hereinafter. The construction of the fitting 62 is such that whenthe fitting is threadedly engaged in the insert 46 with its head 63abutted against the end of such insert, the seat 72 is selectivelylocated in relation to the ball valve.

Contained in the lower portion of the valve housing 36 is a sleeve 74having a plurality of longitudinal recesses 76 on its outer surface andbottom radially extending recesses 78 extending from respective ones ofthe recesses 76 to the inner portion of the sleeve. Recesses 76 and 78form passageways for movement of air from passageway 52 to the lowerportion of the sleeve 74 for flow through the stem 32. Annularpassageway 52 communicates with the counterbore 56 by means of one ormore radial ports 66 through the insert.

Slidably contained in the sleeve 74 is a plunger 82 having an upperintegral stem M which projects through the bore 56 in the insert 66. Thestem M is of a selected length such that when the plunger is raised, thefinger engages the ball valve 68 and lifts it from its seat 70. Theparts are shown in this position in FIG. 2. The tip of the finger isonly slightly spaced from the ball in the down position of the plungerso that the ball is lifted almost simultaneously with the plunger. Theparts are arranged, however, that in the upper position of the plunger,the ball is not pushed into the upper seat 72, whereby the ball cannotbe driven into the seat by the plunger. Otherwise, change may be causedto the plunger and ball from the violent forces of combustion.

As stated above, the air pressure in line 24 is of selected pressuresuch that it is greater than the pressure which may exist in thecombustion chamber during all of the compression stroke of the piston orat least through most of the compression stroke. Such air pressure willkeep the ball valve 68 seated in all strokes of the piston except duringthe latter portion of the compression stroke and of course duringfiring. The ball valve during all the strokes except firing and thelatter portion of the compression stroke will hold the plunger downagainst the bottom of the interior of housing 30 and no movement ofgases from the combustion chamber thus exists upward past the top of thestem 32 during said mentioned times. As the piston moves up in itscompression stroke, it will create a pressure sufficient to raise theplunger 82 in the direction of the arrow thereon in FIG. 2 to unseat theball valve 68. Even though the pressure under the plunger is less thanabove the ball valve, such movement of the plunger results because ofthe enlarged bottom area thereof compared to the area of the ballexposed to the pressure in line 24. As the ball valve moves off the seat70, a charge of fresh air from line 24 shoots past such valve into thecombustion chamber via counterbore 56, radial ports 80, passageway 52,recesses 76 and 78, passageway 34 in stem 32, passageway 42 and throughthe posts 44 into the combustion chamber. As the ball valve moves offsaid seat, such charge of air also acts on the bottom of the plunger toassist in holding the plunger up, thus allowing a good charge of air toenter the combustion chamber.

As ignition occurs, the sudden burst of pressure, being greater thanpressure in line 24, will exist in the opposite direction than that justdescribed and it will seat ball valve 68 on its upper seat 72, toprevent backflow through the valve. As the piston in the engine startsits downward movement and the force of the combustion decreases, theball 68 is forced down against its seat 70 by air pressure in the line24. The plunger 82 is forced down by such ball to its lower position.

FIG. 4 illustrates an embodiment of the invention employing the sameprinciples of the invention. In this embodiment, the numeral 12designates the head of an internal combustion engine and the numeral 86designates a tapped bore through the head which is made for installationof the device. Mounted in the bore 86 is a threaded shank 88 integralwith a valve housing 90. This valve housing has a bore 92 communicatingwith a counterbore 94. Counterbore 94 communicates with anothercounterbore 96 opening through one end of the housing. Bore 92 hascommunication with a pressure line 24 from a pump, such as the pumpshown in FIG. 1, through a suitable fitting 98. The juncture of bore 92and counterbore 94 forms a valve seat 100 for a needle type valve 102operating in the counterbore 94 and integrated with a plunger portion104 operating in counterbore 96. The plunger 104 and its valve 102 areurged toward the bore 92 by a compression spring 106 confined betweenthe plunger and an end plug 108 threadedly connected to the outer end ofcounterbore 96. A passageway 110 in the housing 90 and in the shank 88establishes communication between the counterbore 94 and the end of theshank namely, in the area of the combustion chamber. A passageway 112leads from the forward end of counterbore 96 to an outer edge portion ofthe housing, and a fitting 114 establishes a connection between suchportion of the housing and a line 116. Line 116 extends to thecombustion chamber of another piston in the same engine.

As is well known, the pistons of multiple cylinder internal combustionengines operate in sequence such that when one piston is in its firingstroke another piston is in its compression stroke, and the arrangementof FIG. 4 is such that the firing pressure from one cylinder will openthe valve 102 to allow air pressure to be admitted to the combustionchamber of a piston which is in its compression stroke. That is, it willbe assumed that line 116 extends to one cylinder. When such cylinder isin its firing stroke the high pressure thereof will act on the forwardend of plunger 104 and drive such plunger against the spring in thedirection of the arrow on the plunger to unseat the valve 102 from valveseat 100. This allows a charge of fresh air from line 24 to be injectedthrough bore 92, counterbore 94 and passageway into the combustionchamber. Such movement of air is shown by arrows. As the pressure fromthe firing of the other piston subsides, the spring 106 will reseat thevalve 102, it being understood of course that the spring 106 is of astrength to seat the valve against the pressure in line 24'.

In each of the embodiments of the invention, it is apparent that thecharge of air is injected into the combustion chamber just beforefiring, namely, at a point toward the end of the compression stroke.Such has been found to produce greater efficiency than the introductionof air at other times. It is believed that such greater efficiency isthe result of cold air being admitted into the combustion chamber at themost efficient time, namely, just before firing. The engine runs quietand discharges a very small amount of waste products of combustion. Ithas been found that there is no preignition with a noticeable decreasein exhaust temperatures, and fiirthermore the spark plugs and otherareas exposed to the combustion chamber are maintained in a cleancondition. The system of the present invention can be applied toconventional automobiles, merely by providing ports 44 around the sparkplug mounting bore 20. For the embodiment of FIG. 4, a tapped bore 86 isprovided in the head at the combustion chamber. The pump 22 takes itssupply of air out of the valve cover to produce the necessarylubrication for the valve and to ventilate the valve cover. The parts ofthe valve where necessary are formed from a metal with a high meltingpoint to withstand the temperatures of combustion.

It is to be understood that the forms of my invention herein shown anddescribed are to be taken as preferred examples of the same and thatvarious changes in the shape, size and arrangement of parts may berestored to without departing from the spirit of my invention.

Having thus described my invention, I claim:

1. An air injection system for internal combustion engines comprising a.a valve housing having an inlet and an outlet,

b. means arranged to connect the outlet of said valve housing to aninternal combustion engine with said valve housing in communication withthe combustion chamber of the engine,

c. pressure supply means connected to the inlet of said valve housingproviding a continuous supply of air under pressure, with the pressurethereof being greater than the pressure in the combustion chamberthrough at least most of the compression stroke of the piston in thecombustion chamber,

(1. a ball valve in said valve housing controlling the flow of air'through said valve housing,

e. a plunger on the outlet side of said housing relative to said ballvalve,

f. a stem portion on said plunger arranged for engagement with said ballvalve for unseating the latter,

g. said plunger being arranged through itsstem to unseat said ball valveby movement thereof toward said inlet end by a pressure from thecombustion chamber which is less than the pressure in said pressuresupply means whereby air is arranged to be admitted from said pressuresupply to the combustion chamber during the compression stroke of thepiston in the combustion chamber.

2. An air injection system in combination with an integral combustionengine having multiple cylinders, comprising a. a valve housing havingan inlet and an outlet,

b. means arranged to connect the outlet of said valve housing to aninternal combustion engine with said valve housing in communication withthe combustion chamber of the engine,

c. pressure supply means connected to the inlet of said valve housingproviding a continuous supply of air under pressure, with the pressurethereof being greater than the pressure in the combustion chamberthroughout at least most of the compression stroke of the piston in thecombustion chamber,

d. control means in said valve housing arranged to admit air from saidpressure supply to the combustion chamber during the compression strokeof the piston in the combustion chamber,

e. and means connected between said valve housing and another cylinderof the engine in an arrangement whereby a stroke of said anothercylinder operates said valve to admit air to the first mentionedcylinder.

1. An air injection system for internal combustion engines comprising a.a valve housing having an inlet and an outlet, b. means arranged toconnect the outlet of said valve housing to an internal combustionengine with said valve housing in communication with the combustionchamber of the engine, c. pressure supply means connected to the inletof said valve housing providing a continuous supply of air underpressure, with the pressure thereof being greater than the pressure inthe combustion chamber through at least most of the compression strokeof the piston in the combustion chamber, d. a ball valve in said valvehousing controlling the flow of air through said valve housing, e. aplunger on the outlet side of said housing relative to said ball valve,f. a stem portion on said plunger arranged for engage-ment with saidball valve for unseating the latter, g. said plunger being arrangedthrough its stem to unseat said ball valve by movement thereof towardsaid inlet end by a pressure from the combustion chamber which is lessthan the pressure in said pressure supply means whereby air is arrangedto be admitted from said pressure supply to the combustion chamberduring the compression stroke of the piston in the combustion chamber.2. An air injection system in combination with an integral combustionengine having multiple cylinders, comprising a. a valve housing havingan inlet and an outlet, b. means arranged to connect the outlet of saidvalve housing to an internal combustion engine with said valve housingin communication with the combustion chamber of the engine, c. pressuresupply means connected to the inlet of said valve housing providing acontinuous supply of air under pressure, with the pressure thereof beinggreater than the pressure in the combustion chamber throughout at leastmost of the compression stroke of the piston in the combustion chamber,d. control means in said valve housing arranged to admit air from saidpressure supply to the combustion chamber during the compression strokeof the piston in the combustion chamber, e. and means connected betweensaid valve housing and another cylinder of the engine in an arrangementwhereby a stroke of said another cylinder operates said valve to admitair to the first mentioned cylinder.